a) Field of the Invention
The present invention relates to a method for compensating water for use in an apparatus for treating a photosensitive material, which is adapted to hold constant the concentration of the treatment solution stored within the tanks thereof.
b) Description of the Related Art
In an automatic developing apparatus, which forms part of the apparatus for treating a photosensitive material, a developing tank, bleaching tank, fixing tank, rinsing tank and a stabilizing tank, for example, are each provided, within each tank a developing solution, bleaching solution, fixing solution, rinsing water and a stabilizing solution (hereinafter referred to generally as a treatment solution) are respectively stored. The photosensitive materials, which have been subjected to a stoving treatment, are each sequentially immersed into each treating tank and, after being developed therein, are led to a drying apparatus for drying prior to being withdrawn.
Since the treating solutions are replenished depending on the amount of photosensitive material to be treated, they are to be maintained in a constant composition. However, since there is a decrease of the treating solution due to the evaporation loss of the water contained therein, the treating solution concentration changes thereby deteriorating treatment performance. Therefore, in order to maintain the original concentration of the treating solution, independently of the replenishing solution, it is necessary to compensate the amount of water which evaporates. However, the evaporation loss differs depending on the surrounding environment that is, the humidity and temperature, and also differences depending on whether the apparatus is in operation or not. Therefore, the amount of compensation cannot be definitely determined by calculation.
In view of this, it has been proposed to attach a liquid level sensor such as a float within the treating solution of each treatment tank and to compensate the water based on a value detected by this sensor (See, for example, Japanese Patent Application Publication No. 1-281446), in which the varying concentration of the treating solution can be detected by the liquid level sensor to compensate an appropriate amount of water.
However, since the liquid level sensor is low in reliability and often operates erroneously, it is often impossible to compensate the proper amount of water. This can also be said of a concentration sensor (gravimeter or the like). In addition, these level and concentration sensors are costly and impractical for use. Thus it is proposed to provide a monitoring treatment tank independent from the treatment tanks which are actually used. This monitoring treatment tank compensates water into the treatment tanks based on the amount of evaporation loss (See Japanese Patent Application Publication Nos. 1-254959 and 1-254960). Accordingly, actual evaporation loss and similar data can be obtained thereby improving operational reliability.
However, in the above-described water compensating system, since the monitoring treatment tank is independent from the actual treatment tanks, the entire apparatus becomes bulky. The number of parts required is also increased. In addition, management and maintenance of the monitoring tank become too complicated to achieve a similar working condition for the actual treatment tanks.